<template>
   <!-- 商品分类导航 -->
    <div class="type-nav">
        <div class="container">
            <div @mouseleave="leaveShow" @mouseenter="enterShow">
                <h2 class="all">全部商品分类</h2>
                <transition name='sort'>
                    <div class="sort" v-show="show">
                    <div class="all-sort-list2"  @click="goSearch">
                        <div class="item bo" v-for="c1,index in categoryList" :key="c1.categoryId" 
                        :class='{cur:currentIndex===index}' >
                            <h3 @mouseenter="mouseon(index)" >
                                <a :data-categoryname='c1.categoryName' :data-category1id='c1.categoryId'
                                >{{c1.categoryName}}</a>
                            </h3>
                            <div class="item-list clearfix" :style="{display:currentIndex===index?'block':'none'}">
                                <div class="subitem" v-for="c2 in c1.categoryChild" :key="c2.categoryId">
                                    <dl class="fore">
                                        <dt>
                                            <a :data-categoryname='c2.categoryName' :data-category2id='c2.categoryId'
                                            >{{c2.categoryName}}</a>
                                        </dt>
                                        <dd>
                                            <em v-for="c3 in c2.categoryChild" :key="c3.categoryId">
                                                <a :data-categoryname='c3.categoryName'
                                                   :data-category3id='c3.categoryId'
                                                >{{c3.categoryName}}</a>
                                            </em>
                                        </dd>
                                    </dl>
                                </div>
                            </div>
                        </div>
                    </div>
                    </div>
                </transition>
                
            </div>
            
            <nav class="nav">
                <a href="###">服装城</a>
                <a href="###">美妆馆</a>
                <a href="###">尚品汇超市</a>
                <a href="###">全球购</a>
                <a href="###">闪购</a>
                <a href="###">团购</a>
                <a href="###">有趣</a>
                <a href="###">秒杀</a>
            </nav>
            
        </div>
    </div>
</template>

<script>
import {mapState} from 'vuex'
import _ from 'lodash'
export default {
    name:'TypeNav',
    mounted() {
        if(this.$route.name!=='home'){
            this.show = false
        }
    },
    data(){
        return {
            currentIndex: -1,
            show:true,
        }
    },
    computed:{
        ...mapState({
            categoryList: (state)=>{
                return state.home.categoryList
            }
        })
    },
    methods:{
        mouseon: _.throttle(function(index){
            this.currentIndex = index
        },80),
        // 利用编程式导航+事件委派进行路由的跳转和参数的传递
        // 问题：【需要判断是不是点击的是a标签】
        goSearch(e){
            let node = e.target
            let {categoryname,category1id,category2id,category3id} = node.dataset
            // 有categoryname属性是a标签
            if(categoryname){
                let location = {name:'search'}
                let query = {categoryName:categoryname}
                if(category1id){
                    query.category1Id = category1id
                }else if(category2id){
                    query.category2Id = category2id
                }else{
                    query.category3Id = category3id
                }
                location.query = query
                if(this.$route.params){
                    location.params = this.$route.params
                }
                this.$router.push(location)
            }
        },
        enterShow(){
            this.show = true
        },
        leaveShow(){
            this.currentIndex = -1
            if(this.$route.name!=='home'){
                this.show = false
            }
        }
    }
}
</script>

<style scoped lang='less'>
    .type-nav {
        border-bottom: 2px solid #e1251b;

        .container {
            width: 1200px;
            margin: 0 auto;
            display: flex;
            position: relative;

            .all {
                width: 210px;
                height: 45px;
                background-color: #e1251b;
                line-height: 45px;
                text-align: center;
                color: #fff;
                font-size: 14px;
                font-weight: bold;
            }

            .nav {
                a {
                    height: 45px;
                    margin: 0 22px;
                    line-height: 45px;
                    font-size: 16px;
                    color: #333;
                }
            }

            .sort {
                position: absolute;
                left: 0;
                top: 45px;
                width: 210px;
                height: 461px;
                position: absolute;
                background: #fafafa;
                z-index: 999;

                .all-sort-list2 {
                    .item {
                        h3 {
                            line-height: 28px;
                            font-size: 14px;
                            font-weight: 400;
                            overflow: hidden;
                            padding: 0 20px;
                            margin: 0;

                            a {
                                color: #333;
                            }
                        }

                        .item-list {
                            display: none;
                            position: absolute;
                            width: 734px;
                            min-height: 460px;
                            background: #f7f7f7;
                            left: 210px;
                            border: 1px solid #ddd;
                            top: 0;
                            z-index: 9999 !important;

                            .subitem {
                                float: left;
                                width: 650px;
                                padding: 0 4px 0 8px;

                                dl {
                                    border-top: 1px solid #eee;
                                    padding: 6px 0;
                                    overflow: hidden;
                                    zoom: 1;

                                    &.fore {
                                        border-top: 0;
                                    }

                                    dt {
                                        float: left;
                                        width: 54px;
                                        line-height: 22px;
                                        text-align: right;
                                        padding: 3px 6px 0 0;
                                        font-weight: 700;
                                    }

                                    dd {
                                        float: left;
                                        width: 415px;
                                        padding: 3px 0 0;
                                        overflow: hidden;

                                        em {
                                            float: left;
                                            height: 14px;
                                            line-height: 14px;
                                            padding: 0 8px;
                                            margin-top: 5px;
                                            border-left: 1px solid #ccc;
                                        }
                                    }
                                }
                            }
                        }

                        // &:hover {
                        //     .item-list {
                        //         display: block;
                        //     }
                        // }
                    }
                    .cur{
                        background-color: skyblue;
                    }
                }
            }
            .sort-enter{
                height: 0px;
            }
            .sort-enter-to{
                height: 461px;
            }
            .sort-enter-active{
                transition: all .5s linear;
            }
        }
    }
</style>
